Recommended Use of Reclaimed Asphalt Pavement in the Superpave Mix Design Method

This 2000 report summarizes the research conducted for NCHRP 9-12, Incorporation of Reclaimed Asphalt Pavement in the Superpave System. Chapter 1 reviews the background behind the project and discusses the research approach. Chapter 2 outlines the research findings from all parts of the project. Chapter 3 discusses the implications of these findings. Chapter 4 summarizes the applicable conclusions from this research, makes recommendations for future practice based upon these conclusions and suggests additional research that may be necessary to address some unresolved issues. The main research was conducted in three separate, but related, studies. The "black rock study" investigated the question of whether reclaimed asphalt pavement (RAP) acts like a black rock or whether there is, in fact, some blending that occurs between the old and new binders. The "binder effects study" examined issues related to RAP binder testing including extraction and recovery procedures, applicability of the AASHTO MP1 tests to RAP binders and the effects of RAP content and stiffness on blended binder properties. The "mixture effects study" was directed at assessing the effects of the added RAP on total mixture properties as measured by shear, indirect tensile and beam fatigue testing. Two small-scale investigations, termed "mini-experiments," investigated the comparison of laboratory specimens to plant-produced mixtures and the effects of heating time and temperature on RAP properties.
Content:
Front Matter
• List of Figures
• List of Tables
• Abstract
• Preface
• Table of Contents
• Summary
1. Introduction and Research Approach
2. Findings
3. Interpretation, Appraisal, Applications
4. Conclusions and Suggested Research
• References
Appendices